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71.
提出改进的K-means聚类分割和LVQ神经网络分类的方法,用于有机发光二极管显示面板喷墨打印制程中缺陷像素的识别。首先采用改进的K-means聚类算法对预处理后的打印像素进行分割,然后采用连通域水平矩形确定每一个打印像素的坐标及几何特征,再通过灰度共生矩阵提取其纹理特征,最后通过LVQ神经网络对所述特征进行分类,完成缺陷像素的标记及分类统计。结果表明,本文算法的识别率明显优于其他常用分类识别算法,平均缺陷检测率为100%,分类准确率达到98.9%,单像素检测时间为8.3 ms。 相似文献
72.
基于二体碰撞近似理论(BCA),应用分子动力学(MD)和动力学蒙特卡罗(KMC)方法相结合的多尺度模拟方法,研究了单粒子位移损伤(SPDD)缺陷及电流的演化过程。研究结果表明,SPDD事件中引起的缺陷在106 s内分为3个阶段:阶段Ⅰ(1×10-11 s≤t<2×10-3 s)以点缺陷成团为主;阶段Ⅱ(2×10-3 s ≤t<2×102 s)中以缺陷团内部的间隙原子和空位复合反应为主;阶段Ⅲ(t≥2×102 s)中以小缺陷团发射间隙原子和空位为主。提出一种计算粒子在硅二极管中引起的SPDD电流的方法,推导了多种缺陷存在时引起的二极管反向电流增加的计算公式。基于KMC模拟的位移损伤缺陷演化结果,计算了光电二极管的SPDD电流密度及归一化退火因子。结果表明,KMC模拟计算的退火因子与文献实验测量结果相一致,建立的多尺度模拟方法可预估硅器件的SPDD电流。 相似文献
73.
Bipolar resistive switching (RS) phenomenon without required electroforming has been observed in epitaxial (111)-oriented BaTiO3 (BTO) thin films deposited by PLD technique on conducting Nb-doped substrate of SrTiO3 (NSTO). Negative differential resistance (NDR) is observed at about −5 V when the maximum of positive voltage exceeds 7 V and the compliance current is more than 1.5 mA. And bipolar resistive switching has also been observed. In addition, the resistance of LRS decreases with increasing compliance current or the maximum of positive voltage while that of HRS barely changes, and the resistance of HRS increases with increasing the absolute of maximum of negative voltage while that of LRS scarcely changes. A typical rectifying behavior is observed when the maximum of positive voltage is less than 4 V (such as 2 V). In this case, the reverse biased current is strongly enhanced under illumination of white-light, and vice versa. The resistance of LRS and HRS can be controlled by the applied voltage or the compliance current. The rectifying behavior can be controlled by the white-light. The transition from rectifying behavior to bipolar resistive switching can be controlled by the applied voltage. The above results were discussed by considering the oxygen vacancies that can trap or release electrons as a trapping layer at the Pt/BTO interface. 相似文献
74.
Benzofuranyl benzene incorporating naphthyl (phenothiazinyl or dimesitylboryl) entities via meta-conjugation have been synthesized. These compounds exhibit bipolar transport characteristic with mobilities in the range of 10−5 to 10−4 cm2/V s at an electric field of 4 × 105 V/cm. The compounds with two naphthyl or dimesitylboryl substituents emit in the violet region with good solution quantum yields. The OLEDs fabricated from the benzofuranyl/dimethylboryl, benzofuranyl/naphthyl and benzofuranyl/dimethylboryl/phenathiazine derivatives have maximum external efficiencies of 1.01%, 1.41% and 3.14%, respectively. 相似文献
75.
CaCu3-xNixTi4O12 (x?=?0, 0.05, and 0.10) powders were synthesized using a solid state reaction method. Phase structure and microstructure analyses revealed that all sintered CaCu3-xNixTi4O12 ceramics were of a pure phase. The CaCu3Ti4O12 ceramics had a dense microstructure and grain sizes were enlarged by doping with Ni2+. Interestingly, the dielectric permittivity was significantly enhanced, whereas the loss tangent was greatly suppressed to ~0.046–0.034 at 1?kHz. All sintered ceramics exhibited non-Ohmic characteristics. Clarification of the influences of DC bias showed that the dielectric permittivity and loss tangent values were increased by DC bias. The resistance of grain boundaries and the associated conduction activation energy of CaCu3-xNixTi4O12 ceramics were reduced as the DC bias voltage increased. Therefore, the observed non-Ohmic behavior and significantly enhanced dielectric properties should be closely related to variation in the Schottky barriers at the grain boundaries. 相似文献
76.
Zhongyuan Fu Xinyi Ma Bing Xia Xiaoyun Hu Jun Fan Enzhou Liu 《International Journal of Hydrogen Energy》2021,46(37):19373-19384
Schottky junction and p-n heterojunction are widely employed to enhance the charge transfer during the photocatalysis process. Herein, Cu and Cu3P co-modified TiO2 nanosheet hybrid (Cu–Cu3P/TiO2) was fabricated using an in situ hydrothermal method. The ternary composite achieved the superior H2 evolution rate of 6915.7 μmol g?1 h?1 under simulated sunlight, which was higher than that of Cu/TiO2 (4643.4 μmol g?1 h?1) and Cu3P/TiO2 (6315.8 μmol g?1 h?1) and pure TiO2 (415.7 μmol g?1 h?1). The enhanced activity can be attributed to the collaboration effect of Schottky junction and p-n heterojunction among Cu/TiO2 and Cu3P/TiO2, which can harvest the visible light, reduce the recombination of charge carriers and lower the overpotential of H2 evolution, leading to a fast H2 evolution kinetics. This work develops a feasible method for the exploration of H2 evolution photocatalyst with outstanding charge separation properties. 相似文献
77.
78.
Shih‐Wen Hsiao Yu‐Ting Hsiao Shih‐Kai Chen Chiao‐Fei Hsu Chun‐Hsing Lee Ya‐Hui Chiang 《Color research and application》2016,41(1):72-84
Light‐emitting diodes (LEDs) have the advantage of controllable light colors and provide the optimal lighting quality against various color attributes required in different environments. However, from the humanized design point of view, beside satisfying physical demands of people, it is also important to achieve satisfaction. With a good match between the LED lighting equipment and ambient colors, the space imagery that complies with psychological needs of human beings can be found. This is expected to become a new market direction for future lighting. In this study, the LED light source feature of adjustable correlated color temperature is used to match wall colors of typical commercial spaces and for the investigation and analysis of the impact of colors of light sources and environments on human beings. The measures of mental and subjective feelings of a group of people under various circumstances have also been investigated. Multivariate analysis of variance has been conducted on three color temperatures of light sources, six wall colors, and measures of five emotion adjectives, and the correlation between these three variables has been further investigated. © 2014 Wiley Periodicals, Inc. Col Res Appl, 41, 72–84, 2016 相似文献
79.
Nitrile butadiene rubber loaded with different concentrations of thin graphite nanosheets have been successfully prepared by using a two‐roll mill. The percolation concentration of the nanocomposites was 0.5 phr. The I–V characteristic curves showed that the nanocomposites exhibited ohmic behaviour at a certain voltage and then non‐linear behaviour. The Richardson–Schottky and Poole–Frenkel models were used to investigate the reason for the space charge. The experimental data fit the Schottky model well. The conductivity as a function of temperature was also studied and the data were fitted by using the Mott relation. The Mott relation showed that as the concentration of graphite nanosheets in the rubber composite increases, the hopping distance between the graphite nanosheet layers decreases, which enhances the conductivity of the nanocomposite at low concentrations. Copyright © 2011 Society of Chemical Industry 相似文献
80.
使用轴向寿命控制(CAl-controlled axial lifetime)技术,SEMIKRON将他的第4代续流二极管从1200V扩展到了650V和1700V电压等级。一种创新的终端结构提供了对于极端环境,如湿度影响的高稳定性。此外,这种终端结构使器件能够稳定地工作到175°C。增强型CAL4二极管还对低频及高频等级分别进行了优化,以便获得较好开关特性和较低损耗的最佳折衷。 相似文献